Super Cool: Developer Hacks Foursquare So It Unlocks His Front Door After Checkins

This is easily the most innovative use of Foursquare's API we've seen yet. Two tech enthusiasts, Erin Sparling and Nicholas Hall, have set up their apartment's front door to buzz open when they check in to their home on Foursquare.

They accomplished this "with Foursquare's Alpha 2.0 API, a local push notification service, an industrial web-enabled relay device, some speaker wire, and knowing about electricity." On New Year's Eve, they are setting the program to work for other people, and are using the video below as an invite to their New Year's party.